Field of the Invention
The present invention relates to electronic equipment for home or professional use such as, for example: an Internet gateway, multimedia equipment, etc.
Brief Discussion of the Related Art
Such equipment generally comprises a box containing electronic components that are to be connected to an electrical voltage source. In operation, most electrical components heat up and it is necessary to provide cooling means for preventing the temperature inside the box rising to such an extent as to become incompatible with correct operation of the equipment.
For equipment in which the electronic components heat little or withstand high temperatures, bottom and top openings are provided in the box so as to enable a stream of air to be formed within the box by convection, which stream flows naturally between the bottom and top openings. Natural ventilation is advantageous because of its silence, but it suffers from limited cooling capacity. The heat Q that can be dissipated is equal to h×S×ΔT, where h is the convective heat exchange coefficient, S is the surface area of the item, and ΔT is the temperature difference between the surface and the ambient air. In order to increase cooling capacity, it is therefore necessary to increase the convective heat exchange coefficient, i.e. to increase the number or the size of the openings, or to increase the area of contact with ambient air. This has an impact on the appearance of the equipment by having openings that are more visible and of size that is larger, which impacts make the equipment less attractive to potential users of the equipment. The convective heat exchange coefficient and the surface area of the equipment need to be optimized from the point of view of the heat that is to be dissipated for circumstances that are the least favorable (i.e. when the equipment is in a hot environment and is giving off a maximum amount of heat), whereas such circumstances occur for only a small amount of time in practice.
For equipment having greater cooling needs, bottom openings are provided in the box and a forced ventilation blower is provided that has an inlet in communication with the inside of the box and an outlet opening out to the outside of the box so that, when the blower is in operation, a forced ventilation stream is generated from the bottom openings to the blower. Forced ventilation is advantageous because of its effectiveness and the speed of the blower can be regulated as a function of cooling requirements. Unfortunately, operation of the blower is noisy and requires soundproofing means to be provided. In addition, in order to ensure that the blower is fully effective, it is necessary to provide leaktight ducts between the bottom openings and the inlet to the blower.